The Case for Doxycycline in Our Battle against Filariasis

Abstract

Lymphatic filariasis and onchocerciasis are filarial diseases with potentially debilitating health outcomes as they collectively account for the loss of about 7.2 million disability adjusted life years in both men and women annually. Ivermectin, the major player in the mass drug administration (MDA) programme, has been effective at clearing microfilaria and halting transmission of these infections in some endemic communities. It is however unable to ameliorate the chronic conditions associated with the infections. When anti wolbachial therapy was discovered, an important milestone in the control of filariasis was chalked. Several investigators have since screened many anti wolbachial agents in varied combinations and regimes in order to find a drug/regime that could deplete Wolbachia, kill adult worms, deplete baby worms and ameliorate pathologies associated with these filarial diseases. This scoping review takes a critical look at the literature on anti wolbachial therapy and argues that doxycycline is by far the most promising of the current anti wolbachial drugs under investigation. This is in view of the fact that doxycycline depletes Wolbachia, kills adult worms and indirectly depletes baby worms. Doxycycline also ameliorates chronic pathologies such as lymphedema, hydrocele, dilation in scrotal lymphatics, thickening of the scrotal skin (associated with lymphatic filariasis) as well as dermatitis and ocular diseases (associated with onchocerciasis). Barring a few logistical challenges arising from contraindication in pregnant women and children below 8, doxycycline is relatively safe and does not generate adverse effects associated with rapid killing of worms as with some MDA drugs.